/* TA-LIB Copyright (c) 1999-2025, Mario Fortier
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in
 *   the documentation and/or other materials provided with the
 *   distribution.
 *
 * - Neither name of author nor the names of its contributors
 *   may be used to endorse or promote products derived from this
 *   software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* List of contributors:
 *
 *  Initial  Name/description
 *  -------------------------------------------------------------------
 *  JP       John Price <jp_talib@gcfl.net>
 *
 *
 * Change history:
 *
 *  MMDDYY BY   Description
 *  -------------------------------------------------------------------
 *  070203 JP   Initial.
 *
 */

/**** START GENCODE SECTION 1 - DO NOT DELETE THIS LINE ****/
/* All code within this section is automatically
 * generated by gen_code. Any modification will be lost
 * next time gen_code is run.
 */
/* Generated */ 
/* Generated */ #if defined( _MANAGED )
/* Generated */    #include "TA-Lib-Core.h"
/* Generated */    #define TA_INTERNAL_ERROR(Id) (RetCode::InternalError)
/* Generated */    namespace TicTacTec { namespace TA { namespace Library {
/* Generated */ #elif defined( _JAVA )
/* Generated */    #include "ta_defs.h"
/* Generated */    #include "ta_java_defs.h"
/* Generated */    #define TA_INTERNAL_ERROR(Id) (RetCode.InternalError)
/* Generated */ #elif defined( _RUST )
/* Generated */    #include "ta_defs.h"
/* Generated */    #define TA_INTERNAL_ERROR(Id) (RetCode.InternalError)
/* Generated */    impl Core {
/* Generated */ #else
/* Generated */    #include <string.h>
/* Generated */    #include <math.h>
/* Generated */    #include "ta_func.h"
/* Generated */ #endif
/* Generated */ 
/* Generated */ #ifndef TA_UTILITY_H
/* Generated */    #include "ta_utility.h"
/* Generated */ #endif
/* Generated */ 
/* Generated */ #ifndef TA_MEMORY_H
/* Generated */    #include "ta_memory.h"
/* Generated */ #endif
/* Generated */ 
/* Generated */ #define TA_PREFIX(x) TA_##x
/* Generated */ #define INPUT_TYPE   double
/* Generated */ 
/* Generated */ #if defined( _MANAGED )
/* Generated */ int Core::LinearRegLookback( int           optInTimePeriod )  /* From 2 to 100000 */
/* Generated */ 
/* Generated */ #elif defined( _JAVA )
/* Generated */ public int linearRegLookback( int           optInTimePeriod )  /* From 2 to 100000 */
/* Generated */ 
/* Generated */ #elif defined( _RUST )
/* Generated */ pub fn linearreg_lookback(
optInTimePeriod: i32) -> i32
/* Generated */ #else
/* Generated */ TA_LIB_API int TA_LINEARREG_Lookback( int           optInTimePeriod )  /* From 2 to 100000 */
/* Generated */ 
/* Generated */ #endif
/**** END GENCODE SECTION 1 - DO NOT DELETE THIS LINE ****/
{
   /* insert local variable here */

/**** START GENCODE SECTION 2 - DO NOT DELETE THIS LINE ****/
/* Generated */ #ifndef TA_FUNC_NO_RANGE_CHECK
/* Generated */    /* min/max are checked for optInTimePeriod. */
/* Generated */    if( (int)optInTimePeriod == TA_INTEGER_DEFAULT ) {
/* Generated */ 	  optInTimePeriod = 14;
/* Generated */    } else if( ((int)optInTimePeriod < 2) || ((int)optInTimePeriod > 100000) ) {
/* Generated */ 	  return -1;
/* Generated */ }
/* Generated */ #endif /* TA_FUNC_NO_RANGE_CHECK */
/**** END GENCODE SECTION 2 - DO NOT DELETE THIS LINE ****/

   /* insert lookback code here. */
   return optInTimePeriod-1;
}

/**** START GENCODE SECTION 3 - DO NOT DELETE THIS LINE ****/
/*
 * TA_LINEARREG - Linear Regression
 * 
 * Input  = double
 * Output = double
 * 
 * Optional Parameters
 * -------------------
 * optInTimePeriod:(From 2 to 100000)
 *    Number of period
 * 
 * 
 */
/* Generated */ 
/* Generated */ #if defined( _MANAGED ) && defined( USE_SUBARRAY )
/* Generated */ enum class Core::RetCode Core::LinearReg( int    startIdx,
/* Generated */                                           int    endIdx,
/* Generated */                                           SubArray<double>^ inReal,
/* Generated */                                           int           optInTimePeriod, /* From 2 to 100000 */
/* Generated */                                           [Out]int%    outBegIdx,
/* Generated */                                           [Out]int%    outNBElement,
/* Generated */                                           SubArray<double>^  outReal )
/* Generated */ #elif defined( _MANAGED )
/* Generated */ enum class Core::RetCode Core::LinearReg( int    startIdx,
/* Generated */                                           int    endIdx,
/* Generated */                                           cli::array<double>^ inReal,
/* Generated */                                           int           optInTimePeriod, /* From 2 to 100000 */
/* Generated */                                           [Out]int%    outBegIdx,
/* Generated */                                           [Out]int%    outNBElement,
/* Generated */                                           cli::array<double>^  outReal )
/* Generated */ #elif defined( _JAVA )
/* Generated */ public RetCode linearReg( int    startIdx,
/* Generated */                           int    endIdx,
/* Generated */                           double       inReal[],
/* Generated */                           int           optInTimePeriod, /* From 2 to 100000 */
/* Generated */                           MInteger     outBegIdx,
/* Generated */                           MInteger     outNBElement,
/* Generated */                           double        outReal[] )
/* Generated */ #elif defined( _RUST )
/* Generated */ pub fn linearreg(startIdx: usize,
/* Generated */                  endIdx: usize,
/* Generated */                  inReal: &[f64],
/* Generated */                  optInTimePeriod: i32,
/* Generated */                  outBegIdx: &mut usize,
/* Generated */                  outNBElement: &mut usize,
/* Generated */                  outReal: &mut [f64]) -> RetCode
/* Generated */ #else
/* Generated */ TA_LIB_API TA_RetCode TA_LINEARREG( int    startIdx,
/* Generated */                                     int    endIdx,
/* Generated */                                                const double inReal[],
/* Generated */                                                int           optInTimePeriod, /* From 2 to 100000 */
/* Generated */                                                int          *outBegIdx,
/* Generated */                                                int          *outNBElement,
/* Generated */                                                double        outReal[] )
/* Generated */ #endif
/**** END GENCODE SECTION 3 - DO NOT DELETE THIS LINE ****/
{
   /* insert local variable here */
   int outIdx;

   int today, lookbackTotal;
   double SumX, SumXY, SumY, SumXSqr, Divisor;

   double m, b;
   int i;

   double tempValue1;

/**** START GENCODE SECTION 4 - DO NOT DELETE THIS LINE ****/
/* Generated */ 
/* Generated */ #ifndef TA_FUNC_NO_RANGE_CHECK
/* Generated */ 
/* Generated */    /* Validate the requested output range. */
/* Generated */ #if defined( _RUST )
/* Generated */    /* Skip negative checks for Rust since startIdx/endIdx are usize (unsigned) */
/* Generated */    if( endIdx < startIdx ) {
/* Generated */       return ENUM_VALUE(RetCode,TA_OUT_OF_RANGE_END_INDEX,OutOfRangeEndIndex);
/* Generated */    }
/* Generated */ #else
/* Generated */    if( startIdx < 0 ) {
/* Generated */       return ENUM_VALUE(RetCode,TA_OUT_OF_RANGE_START_INDEX,OutOfRangeStartIndex);
/* Generated */    }
/* Generated */    if( (endIdx < 0) || (endIdx < startIdx)) {
/* Generated */       return ENUM_VALUE(RetCode,TA_OUT_OF_RANGE_END_INDEX,OutOfRangeEndIndex);
/* Generated */    }
/* Generated */ #endif
/* Generated */ 
/* Generated */ #if defined( _RUST )
/* Generated */ 
/* Generated */ #else
/* Generated */    #if !defined(_JAVA)
/* Generated */    if( !inReal ) { return ENUM_VALUE(RetCode,TA_BAD_PARAM,BadParam); }
/* Generated */    #endif /* !defined(_JAVA)*/
/* Generated */    /* min/max are checked for optInTimePeriod. */
/* Generated */    if( (int)optInTimePeriod == TA_INTEGER_DEFAULT ) {
/* Generated */ 	  optInTimePeriod = 14;
/* Generated */    } else if( ((int)optInTimePeriod < 2) || ((int)optInTimePeriod > 100000) ) {
/* Generated */ 	  return ENUM_VALUE(RetCode,TA_BAD_PARAM,BadParam);
/* Generated */ }
/* Generated */    #if !defined(_JAVA)
/* Generated */    if( !outReal )
/* Generated */       return ENUM_VALUE(RetCode,TA_BAD_PARAM,BadParam);
/* Generated */ 
/* Generated */    #endif /* !defined(_JAVA) */
/* Generated */ #endif
/* Generated */ #endif /* TA_FUNC_NO_RANGE_CHECK */
/* Generated */ 
/**** END GENCODE SECTION 4 - DO NOT DELETE THIS LINE ****/

   /* Insert TA function code here. */

   /* Linear Regression is a concept also known as the
    * "least squares method" or "best fit." Linear
    * Regression attempts to fit a straight line between
    * several data points in such a way that distance
    * between each data point and the line is minimized.
    *
    * For each point, a straight line over the specified
    * previous bar period is determined in terms
    * of y = b + m*x:
    *
    * TA_LINEARREG          : Returns b+m*(period-1)
    * TA_LINEARREG_SLOPE    : Returns 'm'
    * TA_LINEARREG_ANGLE    : Returns 'm' in degree.
    * TA_LINEARREG_INTERCEPT: Returns 'b'
    * TA_TSF                : Returns b+m*(period)
    */

   /* Adjust startIdx to account for the lookback period. */
   lookbackTotal = LOOKBACK_CALL(LINEARREG)( optInTimePeriod );

   if( startIdx < lookbackTotal )
      startIdx = lookbackTotal;

   /* Make sure there is still something to evaluate. */
   if( startIdx > endIdx )
   {
      VALUE_HANDLE_DEREF_TO_ZERO(outBegIdx);
      VALUE_HANDLE_DEREF_TO_ZERO(outNBElement);
      return ENUM_VALUE(RetCode,TA_SUCCESS,Success);
   }

   outIdx = 0; /* Index into the output. */
   today = startIdx;

   SumX = optInTimePeriod * ( optInTimePeriod - 1 ) * 0.5;
   SumXSqr = optInTimePeriod * ( optInTimePeriod - 1 ) * ( 2 * optInTimePeriod - 1 ) / 6;
   Divisor = SumX * SumX - optInTimePeriod * SumXSqr;

   while( today <= endIdx )
   {
     SumXY = 0;
     SumY = 0;
     for( i = optInTimePeriod; i-- != 0; )
     {
       SumY += tempValue1 = inReal[today - i];
       SumXY += (double)i * tempValue1;
     }
     m = ( optInTimePeriod * SumXY - SumX * SumY) / Divisor;
     b = ( SumY - m * SumX ) / (double)optInTimePeriod;
     outReal[outIdx++] = b + m * (double)(optInTimePeriod-1);
     today++;
   }

   VALUE_HANDLE_DEREF(outBegIdx) = startIdx;
   VALUE_HANDLE_DEREF(outNBElement) = outIdx;

   return ENUM_VALUE(RetCode,TA_SUCCESS,Success);
}

/**** START GENCODE SECTION 5 - DO NOT DELETE THIS LINE ****/
/* Generated */ 
/* Generated */ #define  USE_SINGLE_PRECISION_INPUT
/* Generated */ #if !defined( _MANAGED ) && !defined( _JAVA )
/* Generated */    #undef   TA_PREFIX
/* Generated */    #define  TA_PREFIX(x) TA_S_##x
/* Generated */ #endif
/* Generated */ #undef   INPUT_TYPE
/* Generated */ #define  INPUT_TYPE float
/* Generated */ #if defined( _MANAGED ) && defined( USE_SUBARRAY )
/* Generated */ enum class Core::RetCode Core::LinearReg( int    startIdx,
/* Generated */                                           int    endIdx,
/* Generated */                                           SubArray<float>^ inReal,
/* Generated */                                           int           optInTimePeriod, /* From 2 to 100000 */
/* Generated */                                           [Out]int%    outBegIdx,
/* Generated */                                           [Out]int%    outNBElement,
/* Generated */                                           SubArray<double>^  outReal )
/* Generated */ #elif defined( _MANAGED )
/* Generated */ enum class Core::RetCode Core::LinearReg( int    startIdx,
/* Generated */                                           int    endIdx,
/* Generated */                                           cli::array<float>^ inReal,
/* Generated */                                           int           optInTimePeriod, /* From 2 to 100000 */
/* Generated */                                           [Out]int%    outBegIdx,
/* Generated */                                           [Out]int%    outNBElement,
/* Generated */                                           cli::array<double>^  outReal )
/* Generated */ #elif defined( _JAVA )
/* Generated */ public RetCode linearReg( int    startIdx,
/* Generated */                           int    endIdx,
/* Generated */                           float        inReal[],
/* Generated */                           int           optInTimePeriod, /* From 2 to 100000 */
/* Generated */                           MInteger     outBegIdx,
/* Generated */                           MInteger     outNBElement,
/* Generated */                           double        outReal[] )
/* Generated */ #elif defined( _RUST )
/* Generated */ pub fn linearreg_s(startIdx: usize,
/* Generated */                    endIdx: usize,
/* Generated */                    inReal: &[f32],
/* Generated */                    optInTimePeriod: i32,
/* Generated */                    outBegIdx: &mut usize,
/* Generated */                    outNBElement: &mut usize,
/* Generated */                    outReal: &mut [f64]) -> RetCode
/* Generated */ #else
/* Generated */ TA_RetCode TA_S_LINEARREG( int    startIdx,
/* Generated */                            int    endIdx,
/* Generated */                            const float  inReal[],
/* Generated */                            int           optInTimePeriod, /* From 2 to 100000 */
/* Generated */                            int          *outBegIdx,
/* Generated */                            int          *outNBElement,
/* Generated */                            double        outReal[] )
/* Generated */ #endif
/* Generated */ {
/* Generated */    int outIdx;
/* Generated */    int today, lookbackTotal;
/* Generated */    double SumX, SumXY, SumY, SumXSqr, Divisor;
/* Generated */    double m, b;
/* Generated */    int i;
/* Generated */    double tempValue1;
/* Generated */  #ifndef TA_FUNC_NO_RANGE_CHECK
/* Generated */  #if defined( _RUST )
/* Generated */     if( endIdx < startIdx ) {
/* Generated */        return ENUM_VALUE(RetCode,TA_OUT_OF_RANGE_END_INDEX,OutOfRangeEndIndex);
/* Generated */     }
/* Generated */  #else
/* Generated */     if( startIdx < 0 ) {
/* Generated */        return ENUM_VALUE(RetCode,TA_OUT_OF_RANGE_START_INDEX,OutOfRangeStartIndex);
/* Generated */     }
/* Generated */     if( (endIdx < 0) || (endIdx < startIdx)) {
/* Generated */        return ENUM_VALUE(RetCode,TA_OUT_OF_RANGE_END_INDEX,OutOfRangeEndIndex);
/* Generated */     }
/* Generated */  #endif
/* Generated */  #if defined( _RUST )
/* Generated */  #else
/* Generated */     #if !defined(_JAVA)
/* Generated */     if( !inReal ) { return ENUM_VALUE(RetCode,TA_BAD_PARAM,BadParam); }
/* Generated */     #endif 
/* Generated */     if( (int)optInTimePeriod == TA_INTEGER_DEFAULT ) {
/* Generated */  	  optInTimePeriod = 14;
/* Generated */     } else if( ((int)optInTimePeriod < 2) || ((int)optInTimePeriod > 100000) ) {
/* Generated */  	  return ENUM_VALUE(RetCode,TA_BAD_PARAM,BadParam);
/* Generated */  }
/* Generated */     #if !defined(_JAVA)
/* Generated */     if( !outReal )
/* Generated */        return ENUM_VALUE(RetCode,TA_BAD_PARAM,BadParam);
/* Generated */     #endif 
/* Generated */  #endif
/* Generated */  #endif 
/* Generated */    lookbackTotal = LOOKBACK_CALL(LINEARREG)( optInTimePeriod );
/* Generated */    if( startIdx < lookbackTotal )
/* Generated */       startIdx = lookbackTotal;
/* Generated */    if( startIdx > endIdx )
/* Generated */    {
/* Generated */       VALUE_HANDLE_DEREF_TO_ZERO(outBegIdx);
/* Generated */       VALUE_HANDLE_DEREF_TO_ZERO(outNBElement);
/* Generated */       return ENUM_VALUE(RetCode,TA_SUCCESS,Success);
/* Generated */    }
/* Generated */    outIdx = 0; 
/* Generated */    today = startIdx;
/* Generated */    SumX = optInTimePeriod * ( optInTimePeriod - 1 ) * 0.5;
/* Generated */    SumXSqr = optInTimePeriod * ( optInTimePeriod - 1 ) * ( 2 * optInTimePeriod - 1 ) / 6;
/* Generated */    Divisor = SumX * SumX - optInTimePeriod * SumXSqr;
/* Generated */    while( today <= endIdx )
/* Generated */    {
/* Generated */      SumXY = 0;
/* Generated */      SumY = 0;
/* Generated */      for( i = optInTimePeriod; i-- != 0; )
/* Generated */      {
/* Generated */        SumY += tempValue1 = inReal[today - i];
/* Generated */        SumXY += (double)i * tempValue1;
/* Generated */      }
/* Generated */      m = ( optInTimePeriod * SumXY - SumX * SumY) / Divisor;
/* Generated */      b = ( SumY - m * SumX ) / (double)optInTimePeriod;
/* Generated */      outReal[outIdx++] = b + m * (double)(optInTimePeriod-1);
/* Generated */      today++;
/* Generated */    }
/* Generated */    VALUE_HANDLE_DEREF(outBegIdx) = startIdx;
/* Generated */    VALUE_HANDLE_DEREF(outNBElement) = outIdx;
/* Generated */    return ENUM_VALUE(RetCode,TA_SUCCESS,Success);
/* Generated */ }
/* Generated */ 
/* Generated */ #if defined( _MANAGED )
/* Generated */ }}} // Close namespace TicTacTec.TA.Lib
/* Generated */ #elif defined( _RUST )
/* Generated */ } // Close impl Core
/* Generated */ #endif
/**** END GENCODE SECTION 5 - DO NOT DELETE THIS LINE ****/

